Rational design of photocatalysts for selective reduction and oxidation

目的：原料选择性还原氧化制高价值化学品是催化技术中的一大挑战，这一过程高度依赖于催化剂的效率，并且对实验条件要求苛刻。该项目的目标是开发强大的光催化剂，以高度选择性地将水还原为氢燃料和/或氧化生物废物。甘油到高价值化学品操作在温和的实验条件下。目标：当今社会面临的一个重大挑战是能源安全。经济可靠的可再生能源和清洁能源合成技术备受追捧。为了减轻大量消耗可耗尽的矿物燃料所造成的环境和能源问题，开发可替代的可再生能源和经济上可行的能源的重要性已得到广泛认识。另一方面，一些便宜但用途广泛的分子，如甘油，可以转化为不同的增值精细化学品和产品。在阳光下，半导体中产生的电子-空穴对可以选择性地将水还原为氢，并选择性地氧化生物废物，以生产用于化学和制药工业的有价值的精细化学品。因此，该项目的目标是开发具有高选择性、高效率、可扩展性和成本竞争力的新型光催化剂，用于氢燃料和精细化学品的生产。为了进一步提高其效率，还将探讨其根本认识。目标包括：(1)设计和合成高效光吸收和水还原的析氢光催化剂；(2)精细化工用选择性氧化光催化剂的设计与合成；(3)利用合适的固体介质进行电荷传递，同时生成氢气和精细化学品。方法：本项目将采用聚合法、化学沉积法和微波水热法对新型光催化剂进行合理设计和合成。然后用XRD， Raman， NMR， BET， UV-vis等方法对其进行表征。用该反应体系分析光催化剂的效率、选择性和稳定性。本课题组的一名成员将通过时间分辨光谱研究光催化剂中的电子转移机理，并将其反馈给光催化剂的选择和结构优化，以进一步提高效率。这属于催化/光催化领域。

Aim: Selective reduction and oxidation of feedstock to high value chemicals is a big challenge in catalysis, which highly depends on the efficiency of the catalyst and always requires harsh experimental conditions. The project targets to develop robust photocatalysts to highly selectively reduce water to hydrogen fuel and/or oxidise biowaste eg. Glycerol to high value chemicals operated under mild experimental conditions. Objectives: A grand challenge facing our society today is energy security. Economical and robust technologies for renewable and clean energy synthesis are highly sought-after. In order to mitigate environmental and energy issues caused by mass consumption of exhaustible fossil fuels, the importance of developing alternative renewable and economically viable energy sources has been widely recognized. On the other hand, some cheap but versatile molecules, like glycerol, can be transformed to different value-added fine chemicals and products. Under sunlight, electron-hole pairs generated in semiconductors could selectively reduce water into hydrogen and selectively oxidise biowaste to produce valuable fine chemicals used in the chemical and pharmaceutical industry. Development of novel photocatalysts with high selectivity, efficiency, scalability, and cost-competitiveness is therefore targeted for hydrogen fuel and fine chemicals production in the project. The fundamental understanding will also be explored in order to further improve its efficiency. The objectives include (1) design and synthesis of hydrogen evolution photocatalysts for efficient light absorption and water reduction; (2) design and synthesis of selective oxidation photocatalysts for fine chemicals production; (3) using appropriate solid medium for charge transfer to generate hydrogen and fine chemicals simultaneously.Methodology: In this project, new photocatalysts will be rationally designed and synthesised by polymerisation, chemical deposition and microwave-hydrothermal method. Then they will be fully characterised by XRD, Raman, NMR, BET, UV-vis spectra etc. The photocatalysts will be analysed to assess their efficiency, selectivity and stability by my reaction system. The electron transfer mechanism in the photocatalysts will be studied by time resolved spectroscopies in collaboration with one member in the group, which will be fed back to photocatalysts selection and structure optimisation in order to further improve efficiency. This is within the domain of catalysis/photocatalysis.